Novel polypeptides and intermediates for the preparation therefor



United States Patent 0 (also 5 3,299,037 Patented Jan. 17, 1967 units and joining these together until the polypeptide V (see below) results and oxidising Compound V to form Compound I.

One method of producing Compound I and its acid addition salts comprises converting the nonapeptide of Formula V,

(IJONH: CH;

CHaOH Phe Ser Asp Cys Pro Lys The present invention relates to a hitherto unknown polypeptide and its salts:

Gly

to the Compound I by oxidising Compound V in aqueous solution at a pH value of from about 4 to about 9 and,

when it is desired to produce an acid addition salt, re-

The polypeptide I may be obtained by methods for the synthesis of peptides in actual use or described inthe' literature on the subject, it being possible to join together the amino acids in the order indicated 1n the above for- 50 sium ferricyanide Solutionmula one at a time or by first forming constituent peptide acting the resulting Compound I with an organic or inorganic acidgthe acid-addition salts are formed by methods known per se. The oxidation may be effected with oxygen, air or an aqueous hydrogen peroxide or potas- C ONH:

CHIOH CH:

Phe Phe Asp Cys I CH,

Pro Lys Gly 3 in which:

R' denotes a radical capable of protecting a sulfhydryl radical in peptide synthesis, and R" denotes a radical capableof protecting an amino radical in peptide synthesis,

by reduction with an alkali metal (e.g. sodium or potassium) in liquid ammonia.

Compound IV may be obtained by condensing a compound of Formula II C ONH:

CHr-CH! CHiOH H:

NIHRII a CH,

i r CH3 Scr Asp Cys Pro in which R and R" have the above significance, with a reactive derivative of a free acid, said free acid having the Formula III It has now been found that Compound I-has an anti diuretic effect almost equal to that of natural lysine vasopressin (vasopressin from pigs, Formula VI) Lys Gly acetic, benzoic, hexahydrobenzoic, methanesulphonic, fumaric, gallic, and hydriodic acid.

The process of the invention may be carried out, for example, as follows:

N-triphenylmethyl-L-serine is condensed with L-asparaginyl S benzyl L cystinyl L prolyl N ep-toluenesulphonyl-L-lysyl-glycinamide to give N-triphenylmethyl L seryl L asparaginyl S benzyl L- cysteinyl L proyl N e p toluenesulphonyl L- lysyl-glycinamide. After splitting oil? the triphenyl radical, the resulting L seryl L asparaginyl-S-benzyl-L- cysteinyl L prolyl N e p toluenesulphonyl L- lysyl-glycinarnide is condensed with N-carbobenzoxy-S- benzyl L cysteinyl L tyrosyl L phenylalanine pnitro-phenyl ester to give N-carbobenzoxy-S-benzyl-L- cysteinyl L tyrosyl L phenylalanyl L seryl L- asparaginyl S benzyl L cysteinyl L propyl N- e-p-toluenesulphonyl-L-lysyl-glycinamide. This nona peptide derivative is treated with an alkali metal, preffrom which the new compound differs in that it contains a serine radical in the place of the glutamine radical. However, as opposed to the natural vasopressins, Compound I has no vasoconstrictive action and is thus suggested for use in therapy as a substance having a specific 7 erably sodium or potassium, in liquid ammonia so that the linear nonapeptide V results. This is converted by oxidation in aqueous solution at a pH value of from about 4 to about 9, preferably with air, oxygen, hydrogen peroxide or potassium ferricyanide, to the biologiantidiuretic effect. The properties of Compound I are cally active, cyclic polypeptide I.

adjuvants which are inert and physiologicallyacceptable.

Examples of such adjuvants are as follows:

Tablets and drageesLactose, starch, talc and stearic acid.

Syrups-Solutions of cane sugar, invert sugar and glucose.

Injectable solutions-Water, alcohols, glycerin and vegetable oils.

Suppositories-Natural or hardened oils and waxes.

The preparations may furthermore contain suitable preserving, stabilizing or wetting agents, solubilizers, sweetening and colouring substances or fiavourings.

The present invention also includes pharmaceutical compositions containing, in addition to a physiologically acceptable carrier, the compound I and/or an acid addition salt thereof.

It should be noted that Compound V above, together with its acid addition salts, and Compounds II above, and also the free hexapeptide II and its acid addition salts wherein R and R" each represent a hydrogen atom, are included in the present invention as well as Compounds IV above.

In the following examples all temperatures are indicated in degrees centigrade.

EXAMPLE 1 (a) N triphenylmethyl L seryl L asparaginyl S- benzyl L cysteinyl L prolyl N e p toluenesulphonyl-L-lysyl-glycinamide 20.5 g. of N-triphenylmethyl-L-serine, 60 g. of L-asparaginyl S benzyl L cysteinyl L prolyl N-ep-toluenesulphonylL-lysyl-glycinamide and 13.4 of dicyclohexyl carbodiimide are dissolved in 300 cc. of dimethylformamide at and the solution is left to stand for 12 hours at 20. Evaporation to dryness is effected in a vacuum, diethyl ether is added to the residue, the resulting precipitate is washed with diethyl ether 7 and dried in a vacuum at 30. 58 g. of N-triphenylmethyl L seryl L asparaginyl S benzyl L- cysteinyl L prolyl N e p toluenesulphonyl L- lysyl-glycinamide are obtained. Melting point 130; [a] --25 (dimethylformarnide).

(b) N carbobenzoxy S benzyl L cysteinyl L- tyrosyl L phenylalanyl L aspaginyl S benzyl- L cysteinyl L prolyl N e p toluenesulphonyl- L-lysyl-glycinam'ide.

g. of N-triphenylmethyl-L-seryl-L-asparaginyl-S- benzyl L cysteinyl L prolyl N e p toluenesulphonyl-L-lysyl-glycinamide are dissolved in 250 cc. of anhydrous trifluoroacetic acid and the solution is left to stand for one hour at 20. After evaporating the solvent in a vacuum at a temperature below 40, the residue is carefully washed with diethyl ether and a solution of 31.5 g. of N-carbobenzoxy-S-benzyl-L-cysteinyl-L-tyrosyl- L-phenylalanine-p-nitro-phenyl ester and 7.5 cc. of triethylamine in 250 cc. of dimethylformamide is added thereto. The mixture is left to stand for 2 days at 20, 1000 cc. of ethyl acetate are subsequently added and the precipitate is washed with ethyl acetate. After drying in a vacuum at 30, 38 g. of N-carbobenzoxy-S- benzyl L cysteinyl L tyrosyl L phenylalanyl L- seryl L asparaginyl S benzyl L cysteinyl L- prolyl-N-e-p-toluenesulphonyl-L-lysyl-glycinamide are obtained. Melting point 208; [a] =55 (dirnethylformamide).

(c) L-cysteinyl L tyrosyl L phenylalanyl L seryl- L-asparaginyl L cysteinyl L pnolyt L lysylglycinamia'e.

.. The necessary amount of sodium or potassium metal is added to a solution of 5 g. of N-carbobenzoxy-S- benzyl L cysteinyl L tyrosyl L phenylalanyl L- seryl L asparaginyl S benzyl L cysteinyl L- prolyl N e p toluenesulphonyl L lysyl glycinamide in 1200 cc. of dry liquid ammonia, whilst stirring at the boiling temperature of the solution, to give a permanent blue colouration. After the addition of 3 g. of ammonium chloride, the solution is evaporated to dryness. The residue contains L-cysteinyl-L-tyrosyl-L- phenylalanyl L seryl L asparaginyl L cysteinyl- L-prolyl-L-lysyl-glycinamide.

(d) Polypeptide I.

The residue obtained from step (0) above is dissolved in 5 litres of 0.01 N acetic acid and oxidized at a pH value of 6.5-8.0 by introducing air or oxygen for one hour at 0-30. The solution is brought to a pH value of 4.0-5.0 and after the addition of 50 g. of sodium chloride or 0.64 g. of methanesulphonic acid or of 0.76 g. trifluoroacetic acid, evaporation to dryness is effected, whereby a dry powder results which keeps well, it may be stored and when used it may be dissolved to give a clear solution. However, the solution may also be used as such, if desired after diluting with Water or a salt solution.

For the purpose of removing the inorganic salts, the above mentioned powder, which results after the addition 'of trifluoroacetic acid, is subjected to a countercurrent distribution in the system secondary butanol/water/trifiuoroacetic acid 1. After 552 transfer stages the compound is present in tubes -210 having a maximum in tube 192 (K=0.55). After evaporation the active polypeptide is obtained in good yield in the form of its hygroscopic trifiuoroacetate, which has been found to be uniform both chromatographically and electrophoretically. Migration in the case of paper electrophoresis at a pH value of 5.8 and 40 V/cm.: 39 mm in 60 min. (the histidine used as the standard migrates 59 mm). Migration in thecase of the paper electrophoresis at a pH value of 1.9 and 40 V/cm.: 110 mm. (the tryptophan used as the standard migrates 110 mm). R; value in the case of paper chromatography in the system isoamyl alcohol/ pyridine/water: 0.77. The total hydrolysis (16 hours, 110, HCl 6 N) yields the following amino acids in equimolar quantities: cystine, serine, asparagine, proline, lysine, tyrosine, phenylalanine, glycine. The product has the following biological activities: 70 IU/mg. on the inhibition of diuresis of the rat and only 3 IU/mg. on the blood pressure of the rat and 1 IU/mg. on the uterus of the rat.

EXAMPLE 2 The same procedure as in Example 1 is used, except that final oxidation is effected at 0-30 by the addition of 7.5 cc. of a N solution of hydrogen peroxide in water at a pH value of 4.0-6.0 (instead of oxidation by introducling air or oxygen).

EXAMPLE 3 The same procedure as in example 1 is used, except that the final oxidation is effected at 0-30 by adding 6.7 cc. of an aqueous 1 N solution of potassium ferricyanide at a pH value of 5.5-7.5.

What we claim is:

1. A compound selected from the group consisting of a polypeptide of the formula and its pharamaceutically acceptable acid addition salts.

2. A compound selected from the group consisting of 20 a polypeptide of the formula and its pharamaceutically acceptable acid addition salts.

wherein R denotes a radical capable of protecting a sulf- 60 hydryl radical in peptide synthesis and R" denotes a radical capable of protecting an amino radical in peptide synthesis.

4. A polypeptide of the formula NHR" (311:

CH: CONH; S-R' GHQ-CH: Hz

CHzOH OH: CH: CH2 CH2 9 wherein R denotes a radical capable of protecting a sulfhydryl radical in peptide synthesis and R" denotes a radical capable of protecting an amino radical in peptide synthesis.

5. L-seryLL-aspara-ginyl-L-cysteiny1-L-pr01yl-L lysylglycinamide.

6. The compound N-triphenylmethyl-L-sery1-L-asparaginy'l S benzyl-L-cysteinyl-L-prolyl-N--p-t0luene-sulphonyl-L-lysyl-glycinamide.

7. The compound N-carbobenzoxy-S-benzyl-L-cysteinyl-L-1yrosyl-L-phenylalanyl-L-seryl-L-asparaginy1-S ben- 1o zyl-L-cysteinyl-L-prolyl-N-e-p-toluenesulphonyl L-lysylglycinarnide.

References Cited by the Examiner 5 UNITED STATES PATENTS 2,854,443 9/1958 Boissonnas et al. 2601l2.5

.LEWIS GOTTS, Primary Examiner.

10 P. A. STITI-I, Assistant Examiner. 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF A POLYPEPTIDE OF THE FORMULA 